1. Field of the Invention
This invention relates to a three-dimensional measuring apparatus for measuring an inspected object in relation to its three-dimensional positioin.
2. Related Art Statement
Recently, an endoscope has come to be extensively used in the medical and industrial fields.
For example, in an observed image by an ordinary endoscope, generally the inspected part is plane and the unevenness is hard to recognize. Therefore, for example, in the publication of a Japanese patent application laid open No. 24215/1989 is disclosed an apparatus wherein two systems of objective lenses are provided in the tip part of an endoscope so that two picture images obtained by these two systems of objective lenses may be led to an eyepiece part through an image guide to obtain a cubic visual field by binoculars. Also, in the publication of a Japanese patent application laid open No. 46927/1983 is disclosed a stereo-visible endoscope provided in the tip part with two imaging optical systems and two solid state imaging devices.
However, with such endoscope, though a cubic visual field can be obtained, there has been a disadvantage that the distance to the image within the visual field can not be obtained.
A technique for dissolving this disadvantage is disclosed in the publication of a Japanese patent application laid open No. 63432/1988. In this technique, as shown in FIG. 51(a), in order to designate measuring object points in the space, the positions of measuring object points in the respective images are given by a pointing device or the like on a plurality of images having parallaxes and thereby straight lines in the space passing through the imaging means imaging the images and the measuring object points are determined. When the positions of the measuring object points are given on the respective images by a plurality of imaging means arranged in the positions having parallaxes, a plurality of straight lines will be thereby determined in the space. Generally, the straight lines in the space can not be said to always have intersections but should all pass through the measuring object points. Therefore, if the positions are well accurately designated, the positions of the measuring object points for the imaging means in the space will be able to be calculated as the intersections of these straight lines.
However, there has been a problem that, in an endoscope image, the object wanted to be measured is not always accompanied with a clear feature point and, in case there is no clear feature point, the position designation on the respective pictures of the measuring object points will be likely to be inaccurate. Therefore, as shown in FIG. 51(b), the straight lines in the space to pass through the measuring object points will have no intersection and the distance has not been able to be measured.
Now, as a means of designating the points on the pictures of the respective monitors, for example, it is considered to designate the points by displaying cursors on the pictures of the respective monitors and moving these cursors to desired positions.
However, there has been a problem that, if such means of moving the above mentioned cursors as, for example, mice are separately provided for the cursors of the respective pictures, the operation will be complicated.
Further, there is a problem that, if cursors are displayed on the pictures of both monitors, the cursor on which picture is the moved cursor and on which picture the points can be designated are hard to know.
Though the size of the object can be numerically known as described above, on the other hand, it is desired to directly know the size of the object by sight.